This invention pertains to railroad cars and more particularly to a structure of a freight spine car.
Spine cars carry freight containers mounted on a spine-like car platform. A spine car generally includes a center beam with a series of parallel crossbearers extending transversely of the beam.
The containers are generally detachably secured on a spine car by container locks on crossbearers or bolsters on the car. These locks receive vertical loads for the weight of the containers. The locks also receive impact loads in a horizontal plane in resisting the tendency of a container to slide off the car during acceleration, deceleration, or cornering of the car.
Weight of a railway car is at a great premium, and reducing weight is an important goal of railway car design. To reduce weight by reducing the number of wheeled trucks needed in a railway car train, it is well known in the prior art to provide an articulated connection between two cars wherein an end of each car is pivotally supported on a truck. To limit tilt of the car with respect to the truck, the cars are usually provided with side bearing arms extending over the truck laterally outward of the pivotal connection. The side bearing arms contact bearings on the truck, preventing significant tilting of the car with respect to the truck.
However, no spine car is presently available which supports containers while taking advantage of the use of articulation between cars, and more particularly provides an efficient railway car structure for bearing horizontal impact loads from container locks and loads from side bearing arms.
Various spine cars heretofore disclosed are exemplified in the following patents. U.S. Pat. No. 3,616,764, issued to Johnson et al., shows a railway container car including a pair of I-beam side sills and a boxlike center sill interconnected by an angled cross member. Another U.S. Pat. No. 4,274,776, issued to Paton et al., teaches a container railcar with a depressed midsection and a four point truck suspension.